1. Field of the Invention
This invention relates to a manual gas valve for a gas appliance that can be easily and reliably converted for use with either natural gas or Liquid Propane (LP) gas and that provides a similar heating value using either natural gas or LP gas.
2. Description of the Related Art
It is well known to those skilled in the art that natural gas and LP gas have different heating values, and are supplied to a gas appliance under different pressures or flows. Several solutions have been proposed to operate with either natural gas or LP gas, such as: (1) exchanging the existing valve for a valve with a different flow rate; (2) reducing the pressure of the LP gas further after it flows out of its original pressure reducing valve; and (3) adopting a conical valve to regulate the gas flow at a low level on a special tester and replacing the nozzles with nozzles having different orifice diameters to change the gas flow at a high level. All of these solutions are a great inconvenience and carry a substantial cost increase associated with conversion. Accordingly, there is still a need for a valve that can be reliably and effectively converted from the use of natural gas to the use of LP gas.